1. Technical Field
The present disclosure relates to electromagnetic relays, and more particularly to electromagnetic relays having a housing open towards the terminal end of the relay, a magnet system with a coil and a free-floating armature arranged in the upper, closed portion of the housing, and a contact system which is arranged in the lower open portion of the housing and has at least one moveable contact element that is operationally connected to the armature.
2. Background of Related Art
Electromagnetic relays are known, for example, in automotive applications requiring the switching of intermediate level currents, e.g., from 10 to 30 Amps. Such relays sometimes utilize a free-floating armature in a dual-in-line socket mounting arrangement. The relay is normally enclosed in a protective housing to provide shielding from dust and other undesirable particulates.
One problem associated with such free-floating armature or "telephone-style" relays, is that in a particular operating environment, free motion of the relay may produce audible sounds as the assembly experiences shocks and vibrations. Such vibratory operating conditions are common, for example, in automotive applications where these sounds often prove to be unacceptable.
Another problem associated with free-floating armature type relays is that less consistent operation of the relay may result, e.g., if the armature is displaced to one side or the other. In particular, increased friction may arise in the armature hinge structure. Such a condition impedes optimal operation of the relay resulting in a variation of the actuation voltage.
A further problem with free-floating armature relays is that the armature is subject to binding and variable sensitivities resulting from inconsistent air gaps in the armature's hinge structure.
Previous attempts to overcome these problems involved retention of the armature through the use of additional parts. For example, additional springs, mounting brackets as well as associated hardware have been utilized to dampen movement of the free floating armature. However, such remedies increase the time and cost required to manufacture and assemble each unit.
Another problem encountered during the assembly of some conventional relays is that contact forces, gaps and overtravel normally have to be set after the relay is completely assembled. Unfortunately, this is when it is the most difficult to access the parts involved.
Despite these earlier efforts to overcome the problems associated with free-floating armatures, a need still exists for an improved armature retaining arrangement which does not add significantly to the per unit manufacturing and assembly costs of the relays. A need also exists for a modular electromagnetic relay which overcomes the problems associated with making final adjustments and settings to the relay.